Portable incinerator



Nov. 9, 1954 I J. s. DEMPSTER 2,693,773

PORTABLE INCINERATOR Filed April 11, 1951 2 Shee ts-Sheet-l mrzwwgwmm ATTORNEKS' Nov. 9, 1954 Filed April 11, 1951 J. S. DEMPSTER PORTABLE INCINERATOR 2 Sheets-Sheet 2 INVENTOR ATTORNEYS 2,693,773 Patented Nov. 9, 1954 PORTABLE INCINERATOR John S. Dempster, Knoxville, Tenn., assignor to Dempster Brothers, Incorporated, Knoxville, Tenn., a corporation of Tennessee Application April 11, 1951, Serial No. 220,436 11 Claims. (Cl. 110-18) This invention relates to an improved portable incinerator and especially to the provision of improved means facilitating the removal of ashes and burned resldues from such a device.

One of the objects of the invention is to provide an improved portable incinerator of novel construction such that it functions effectively as an incinerator while at the same time it can be transported readily to any desired location either for further use as an incinerator or for the purpose of removing ashes therefrom.

Another object is to facilitate the removal of ashes and like residues from an incinerator of the above type by the provision of a drop bottom together with means whereby the incinerator can be first elevated and its bottom then opened to discharge the ashes and clean the incinerator for further use.

A further object is to provide an improved incinerator as characterized in the preceding object and wherein the usual grill or grate supporting the materials to be burned forms part of the drop bottom so that residues remaining on the grate as well as those which drop through the grate can be dumped simultaneously.

A still further object is to provide an improved portable incinerator of the type characterized above which is constructed and arranged so that it can be handled by a transporting and dumping vehicle of the type illustrated for example by U. S. Patent No. 2,179,779.

Another object is to provide an improved portable incinerator of the above type having a ventilated doublewalled construction and comprising an inner shell insertable in and removable from the outer shell together with novel means for securing the two shells together in properly spaced relation.

In cases where secret documents have to be destroyed by burning, as is often the case in Government oflices, for example, a portable incinerator of the type characterized above can be moved readily from place to place to incinerate successive charges of papers to be destroyed, and when it becomes filled or substantially filled with burned residues, it can be carried away to any desired location for disposal of such residues in any suitable manner. For such purposes it is another object of the invention to construct and arrange the incinerator in such a way that papers or documents to be destroyed can be placed in the incinerator and burned under the supervision of the responsible persons, such papers and their residues being inaccessible to unauthorized persons after having once been charged into the incinerator.

One embodiment of the invention has been illustrated in the accompanying drawings, but it is to be expressly understood that said drawings are for purposes of illustration only and are not to be construed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings,

Fig. 1 is a plan view of an incinerator embodying the invention, part of its walls being removed to show its interior construction;

Fig. 2 is a side view of half of the figure being center line of Fig. 1;

Fig. 3 is an end view of the incinerator, the left-hand half of the figure being in section on the vertical center line of Fig. l; and

Fig. 4 illustrates the dumping of the incinerator by means of a vehicle of the type disclosed in the aforesaid patent.

the incinerator, the right-hand in section on the horizontal The incinerator may have any desired cross sectional shape but preferably and as shown in the drawings it comprises a rectangular body having spaced inner and outer rectangular metal walls 1 and 2 respectively. The space 3 between these walls forms a ventilated space as hereinafter described. The upper portion of the incinerator body may suitably be of truncated pyramidal form, the outer walls 1 being continued by inclined panels 4 and the inner walls 2 being continued by similar inclined panels 5. At the top of the incinerator, the panels 4 terminate in a flat horizontal top section 6 having a central opening in which is secured a tubular neck 7 open at the top. The inner panels 5 similarly terminate in a tubular neck 8 concentric with and disposed within the neck 7.

The walls 1, 4 and 7 together form the outer shell of the incinerator, and the Walls 2, 5 and 8 form a correspondingly shaped inner shell which may be inserted as a unit into the bottom of the outer shell. The two shells are connected in spaced relation at the top by means of suitable spacers 9 and bolts 10, the spacers being interposed between the tubular necks 7 and 8 and the bolts extending through both necks and through the spacers 9. The inner shell is thus supported by the outer shell at the top, and is preferably located properly and held firmly at the bottom by suitable means such as a spacer flange 11 secured in any suitable manner to the outer shell and projecting inwardly into engagement with the lower edge of the inner shell. The flange 11 may comprise a series of separate spaced flanges if desired, but preferably extends continuously around the inner shell. Accordingly this flange forms a bottom for the ventilated space 3 between the inner and outer shells, this space being open at the top between the necks7 and 8 and air being admitted to it near the bottom by suitable openings 12 in the outer shell walls 1.

The inner shell walls 2, 5 enclose an incinerating space 13 which is open at the top through the neck 8 for the escape of combustion gases. Preferably a wire screen 14 is formed so as to fit over the outer neck 7 to prevent the escape of burning materials from the incinerator.

The walls of the outer shell are preferably reenforced by suitable angles 15 and 16, the angles 15 along the rear wall of the incinerator being preferably secured to its inner surface so as to leave a flush outer surface for a purpose described below. On the front wall of the in cinerator, however, the angles 16 are preferably secured to the outer surface of the wall.

The bottom of the incinerator comprises a drop bottom which is suitably pivoted on and closes the bottom of the outer shell 1, and a suitable grill or grate that is mounted on the drop bottom in position to close the bottom of the inner shell 2. In the form shown, the outer walls I extend below the spacer flange 11 and below the lower edge of the inner walls 2. Along one side of the incinerator, the lower edge of its outer wall 1 is flanged inwardly and strengthened by a brace plate 17 to support hinge members 18. The bottom 19 is provided with cooperating aligned hinge members 20 and hinge pins 21 extend through the aligned hinge members 18 and 20. The bottom 19 can be secured and if desired locked in closed position by suitable means such as a hasp 22 on the side opposite the hinges which engages an eye 23 secured to one of the strengthening angles 16. As shown, the bottom 19 is further strengthened by means of channel iron braces 24 secured to its lower surface and resting on the ground when the incinerator is in use.

The grill or grate 25 is mounted on the drop bottom in spaced relation thereto by means of suitable supports such as short sections of channel iron 26 that are suitably arranged as indicated in Fig. l. The spacing between the grill 25 and the bottom 19 is such that when said bottom is closed, the edges of the grill fit closely against the lower edges of the inner walls 2 to complete the incinerator space 13. Combustion air is admitted beneath the grate by means of openings 27 in the outer shell walls.

A suitable charging door is provided near the top of the incinerator. In the form shown, hinges 28 are se- 'is desired to dump the incinerator, on the cured to one of the inclined wall panels 4 whereby a charging door 29 is hinged in position to close a charging opening formed in said panel 4. This door can be fastened in closed position, and if desired locked in closed position, by suitable means such as a hasp 30 secured to the edge of the door opposite the hinges 28 and adapted to engage an eye 31 secured to the strengthening angle 16. A similar aligned charging opening is formed in the inclined panel of the inner shell, which opening is preferably closed by an inner door section 32 suitably connected to the outer door 29 as by means of connecting members 33 so that both door sections swing as a unit on the hinges 28.

Preferably the incinerator is adapted for handling by a transporting and dumping vehicle of the type disclosed in the patent mentioned above.' For example, the ends of the bottom 19 are provided with triangularly shaped, upwardly extending walls 34 and the end wall panels 1 of the outer shell are correspondingly cut away, the edges of the panels 1 and walls 34 meeting when the bottom 19 is closed to form the end walls of the incinerator. In closed position, these meeting edges are preferably covered by outer guide plates 35 as shown on the righthand side of Fig. 3 and by inner guide plates 36 as shown on the left-hand side of Fig. 3. Adjacent the apex of each triangular wall 34 is secured a plate 37 provided with a lifting pin 38. At the upper part of the vertical rear wall 1 of the incinerator is a suitable bail 39.

When the incinerator is to be moved, it is picked up by a transporting and dumping vehicle of the type mentioned above as shown diagrammatically in Fig. 4. As described in the aforesaid patent, the vehicle is provided at its rear end with an inclined skid frame 40 which is movable on the vehicle in a fore and aft direction, and with incinerator supports 41. The vehicle is also provided with lifting arms or booms 42 carrying lifting chains 43 which terminate in suitable connecting members 44 adapted to engage the lifting pins 38. With the skid frame 40 in the rear position shown in Fig. 4, the vehicle is backed up to the rear wall 1 of the container resting on the ground, the booms 42 are lowered, and the members 44 are engaged with the lifting pins 38. When the booms 42 are elevated, therefore, the incinerator is lifted along the skid frame 40, the flushsurfaced rear wall 1 sliding along this frame and the drop bottom 19 being held closed by the lifting action. The skid frame 40 can then be moved forwardly and the booms 42 lowered slightly to deposit the container on the supports 41.

When the desired location is reached, the incinerator can be returned to the ground by elevating the booms 42 to lift the incinerator from the supports 41, moving the skid frame 40 to the rear, and then lowering the booms 42 until the incinerator rests on the ground. When it other hand, the booms 42 are elevated to lift the incinerator from the supports 41, the skid frame 40 is moved back to its rear position as shown in Fig.4, and the incinerator is further elevated by the booms 42 until its bail 39 engages asuitable dumping hook 45 at the top of the skid frame. When the booms 42 are now lowered, the incinerator is held in the elevated position shown in Fig. 4 by the bail 39, but the drop bottom 19 swings open by its own weight to discharge all burned residues.

. The empty container can thus be transported to any desired location for incineration purposes. It may be left in one location until filled with burned residues, or it may be moved from place to place until filled. In the case of secret papers or documents, the bottom door 19 and the charging door 29 can be locked and 'the documents within the inner shellare thus completely inaccessible. The burned residue can' be left in the incinerator while successive charges are added from time to time and burned and 'until the'incinerator is filled to any desired extent, whereupon it is carried away, dumped as described above, and then returned for further use.

While only one embodiment of the invention has been described and illustrated in the drawings, itwill be' understood that this embodiment is by way of example only and that various changes can be made in the form, details of construction, and arrangement of the parts Without departing from the spirit of the invention. Reference should therefore 'be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. A portable incinerator comprising a double-walled incinerator body, the innerwall forming a combustion chamber and having a top opening for the escape of combustion gases, the outer and inner walls forming a ventilating space around said combustion chamber, said body having openings adjacent its bottom for admitting combustion air into said chamber and ventilating air into said space and a drop bottom hinged to said body and supporting the materials to be burned in said chamber and the burned residues therein, sections of said outer wall being cut away from its bottom edge upwardly at circumferentially spaced points, said drop bottom having upwardly extending side walls corresponding in size and shape with said cutaway sections and fitting in the latter when said bottom is closed to complete the outer wall of the ventilating space, the upper portions of said side walls carry lifting means for lifting said drop bottom to closed position and also for lifting said incinerator bodily while holding said drop bottom in' closed position, and incinerator suspension means on the incinerator body independent of said drop bottom and lifting means whereby lowering of said lifting means relative to the suspended incinerator body causes said drop bottom to open to discharge said residues.

2. A portable incinerator as defined in claim I, having aligned charging openings in its inner and outer walls adjacent its top, and a hinged charging door comprising spaced sections adapted to close said openings.

3. A portable incinerator as defined in claim 2, including means for locking said charging door and said drop bottom in closed positions for preventing access. to the contents of the incinerator.

4. A portable incinerator comprising an inner wall forming an incinerating chamber and having a top opening for the escape of combustion gases, an outer wall surrounding and spaced from said inner wall, the space between said walls being open at the top of the incinerator and said outer wall having openings adjacent the bottom of the incinerator for admitting ventilating air to said space, a bottom closure member hinged to said outer wall, a grate structure mounted on said closure member and forming the bottom of said incinerating chamber, said outer wall also having openings admitting combustion air below said grate, lifting means on said closure member whereby the incinerator may be elevated, and means on said outer wall for supporting the incinerator in elevated position whereby said closure member opens on lowering said lifting means.

5. A portable incinerator comprising an inner shell enclosing an incinerating space and having a top opening for the escape of combustion gases, an outer shell surrounding said inner shell in spaced relation, said shells forming between them a ventilating space open at the top, said outer shell extending below said inner shell, a door hinged to said outer shell for closing the bottom of the incinerator, and a grate structure mounted on said door in position to cooperate with said inner shell and form the bottom of said incinerating space when said door is closed, said outer wall having openings for admitting ventilating air to said ventilating space and combustion air to said incinerating space.

6. A portable incinerator as defined in claim 5, having adjacent its top aligned charging openings in said inner and outer shells and including a charging door comprising sections of said inner shell and outer shell that afienconnected together and hinged as a unit on said outerv s e 7. A portable incinerator as defined in claim 6, both said doorshaving locking means forpreventing access to said incinerating space. I

8. A portable incinerator comprising spaced inner and outer shells both open at the top, spacer means for securing said shells together at the. top, said outer shell extending below said inner shell and having a spacer flange projecting inwardly into engagement withsaid inner shell adjacent its bottom edge, a bottom door hinged to and closing said outer shell, a grate structure carried by said bottom door in position toform the bottom of said innerv shell when said door is closed, said inner and outer shells having aligned charging openings ad.- jacent the top of the incinerator, and a charging door hinged on said outer shell and comprising spaced inter: connected members for closing said inner and outer she openings, said outer shell having openings above said spacer flange for admitting ventilating air to the space between said shells and below said spacer flange for admitting combustion air beneath said grate.

9. A portable incinerator as defined in claim 8, said shells tapering toward the top of the incinerator and terminating in concentric neck portions, and a cover screen fitting the outer neck portion.

10. A portable incinerator as defined in claim 8, said outer shell having a bail for supporting the incinerator in an elevated position in which said bottom door can swing open to discharge burned residues.

11. A portable incinerator as defined in claim 10, said bottom door having projecting lifting pins whereby the incinerator can be elevated while holding said bottom door closed.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,124,529 Rudd Jan. 12, 1915 1,194,385 Hoover Aug. 15, 1916 1,440,141 Eshelman Dec. 26, 1922 1,576,289 Ledden Mar. 9, 1926 1,630,393 Ledden May 31, 1927 2,244,024 Schadek June 3, 1941 

